1. Field
Embodiments of the invention generally relate to methods of thermally processing substrates, and more particularly to methods of depositing a layer on a substrate.
2. Description of the Related Art
Semiconductor manufacturing relies on chemical processes to deposit, remove, clean, and otherwise transform materials formed on a substrate. These processes typically occur in a reactor that applies thermal or electrical energy to accelerate the chemical processes. In some cases, low energy photons are used to add thermal energy. In other cases, higher energy photons are used to dissociate molecules before they enter the reactor. In still other cases, higher energy photons are used to transform materials on a substrate.
For the very shallow circuit features required for advanced integrated circuits, it is greatly desired to reduce the total thermal budget in achieving the required thermal processing. The thermal budget may be considered as the total time at high temperatures necessary to complete device fabrication. The greater the total time that the substrate is subject to high temperatures, the more features such as implanted junctions may loose their definition due to diffusion or migration of atoms. However, the conventional approaches of activating chemical processes for semiconductor applications are typically energy-intensive and therefore are not suitable for most device fabrication. For example, substrates for CMOS devices typically have a temperature threshold at about 400° C. Furthermore, even at higher temperatures, current CVD, ALD or epitaxial process still requires long deposition times, which undesirably reduce the throughput.
Therefore, there is a need for an improved apparatus and methods for a substrate process that promotes low temperature depositions at faster processing time.